Recently, in order to prevent global warming, it has been required to reduce emission of carbon dioxide into atmosphere.
As one of the means for carbon dioxide capture and storage (hereinafter, often referred to as “CCS” in the present specification), there is a recovering method based on chemical adsorption. That recovering method has hitherto played an important role in reducing carbon dioxide contained in combustion gases exhausted from boilers in, for example, thermal power plants.
Specifically, a representative CCS process is carried out in the following manner.
First, a combustion gas exhausted from boilers is subjected to treatments, such as, denitration, dust collection, and desulfurization, according to necessity. The gas is then introduced into an absorption tower, in which the gas is brought into contact with an absorption solution so that CO2 in the combustion gas may be absorbed therein and thereby removed from the combustion gas. The solution thus absorbing CO2 is heated by means of, for example, a heat exchanger, and then introduced into a regeneration tower. In the regeneration tower, CO2 is dissociated and recovered from the absorption solution. After experiencing dissociation of CO2 in the regeneration tower, the absorption solution is circulated again into the absorption tower and reused for absorbing CO2 in the combustion exhaust gas.
The absorption solution used in the above CCS process preferably comprises an amine and water.
In performing the above CCS process based on chemical adsorption, it is necessary to be so careful that the amine and degradation products thereof in the absorption solution may not leak out from the CCS apparatuses, such as, the absorption tower, the regeneration tower, and the like. For the purpose of that, it is required to provide methods for recovering and analyzing the amine serving as a component of the absorption solution and degradation products thereof. Specifically, as for nitrosoamines in particular, it is desired to provide techniques of high-level recovering and of highly-sensitive quantitative analysis because they are considered to be hazardous compounds.